Company - Transport for London    

How was this solved?

The project had to show that London Underground could measure, monitor and reduce the carbon emissions associated with major project delivery, working closely with suppliers to identify innovative ways to reduce emissions and improve project value. The project was committed to achieving this through: 

  • Building whole life carbon into the project;
  • Incorporating carbon reduction into procurement requirements; and
  • Collaboration with the supply chain to stimulate innovation.

The assessment of carbon reduction ideas for CTSCU relied upon a Concept baseline which was developed using the RSSB Rail Carbon Tool. This baseline allowed the project to identify carbon hotspots to focus on during the value engineering exercise. This baseline was also provided to bidders during the initial Invitation to Tender (ITT) stage.

The project engaged early with the supply chain by embedding a question within the ITT that focused on reducing carbon and following the principles of the Infrastructure Carbon Review (ICR). The question accounted for 5% of the total ITT scores. This allowed the project to source numerous value ideas from a range of suppliers that could be used as the basis for developing a plan to deliver the project’s targets. This question was well received by the supply chain and resulted in a large list of over 100 ideas that could generate additional value and improve sustainability.

As the procurement process continued, the project team collated value ideas and combined them with additional ideas elicited from internal stakeholder workshops. All of these options were then presented during a mobilisation workshop where they were assessed for their potential impact and ease of implementation. The top 20 ideas were then assembled along two design spines which formed the basis of the value engineering exercise. These design spines provided a structured process along which the project could develop options and focus on increasing value.

In order to assess options against each criterion the project developed a sliding scale with top score being awarded for hitting stretch targets. A whole life carbon reduction target of 40% was benchmarked against what other infrastructure companies, such as Anglian Water and National Grid, were achieving on their own schemes. This stretch target pushed the supply chain to deliver innovative ideas if they were to score highly in the Value Model.

Following the successful completion of this exercise, the project presented its efficiencies to senior leadership within London Underground to raise awareness of the value of including carbon reduction within the requirements of future projects.

What were the outcomes?

The project was a clear success which has resulted in a more sustainable scheme, the development of carbon management processes and successfully raised the profile of carbon reduction within TfL’s capital programme portfolio.

Perceived value has increased by 29% against a target of 15%. And 9.2% of this can be directly attributed to carbon reduction.   

The project has demonstrated a whole life carbon saving of 11.8million kgCO2e. This constitutes a 27% reduction in whole life carbon from the original Concept baseline model.   


  • Carbon Smart, supporting the economy

Asset/ operations

  • Asset   

Organisation type

  • Infrastructure